81788455 has 16 divisors (see below), whose sum is σ = 114071040. Its totient is φ = 55131552.

The previous prime is 81788423. The next prime is 81788461. The reversal of 81788455 is 55488718.

It is not a de Polignac number, because 81788455 - 2⁵ = 81788423 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 17739 + ... + 21868.

It is an arithmetic number, because the mean of its divisors is an integer number (7129440).

Almost surely, 2^81788455 is an apocalyptic number.

81788455 is a deficient number, since it is larger than the sum of its proper divisors (32282585).

81788455 is a wasteful number, since it uses less digits than its factorization.

81788455 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 39678.

The product of its digits is 358400, while the sum is 46.

The square root of 81788455 is about 9043.6969763477. The cubic root of 81788455 is about 434.0742279263.

The spelling of 81788455 in words is "eighty-one million, seven hundred eighty-eight thousand, four hundred fifty-five".